A timepiece of this type is disclosed, for example, in WO Patent application No 00/36473. This patent application discloses and shows a watch including an external bolt for controlling the sliding of the piston, against the return force of a helical compression spring which is arranged around a stem forming the piston. The spring is inserted between the inner sliding block and the edge of a guide hole for the stem.
The control surface is arranged at the free end of the piston. It abuts against an arm which actuates the striking mechanism. This arm is generally pivotably connected to a pivoting rack which winds a striking barrel and which releases the striking mechanism. The angular travel of the rack varies as a function of the time to be indicated.
When the user wishes to release the striking mechanism, he moves the bolt against the return spring. When the rack has travelled an angular distance determined by the time to be indicated, it is stopped, which blocks the sliding of the piston and the sliding of the bolt.
However, the user does not always cease pressing on the bolt as soon as it reaches the stop. Thus, the rack and the other parts of the striking mechanism which are connected thereto are subjected to the pressure applied by the user, which can cause a malfunction of the striking mechanism, or even damage the latter.
It is an object of the invention to overcome these drawbacks.